For relative low pressure, low capacity reciprocating piston compressors, a valve plate containing inlet and outlet ports is clamped between a cylinder and a cylinder head. Valves reeds are riveted or otherwise attached to opposite sides of the valve plate to form check valves which allow air to flow through the inlet port into the cylinder during the intake or suction stroke of the piston and to to flow through the outlet port during the compression stroke.
Problems are often encountered during manufacture of compressors having reed valves. The prior art valve plate assemblies are relative expensive to manufacture and tend to leak, which as a consequence reduces the output from the compressor. The metal valve reeds are subject to bending during assembly handling. Therefore, it is necessary to test each compressor after it is assembled and it often is necessary to partially dismantle a newly manufactured compressor to replace a faulty valve plate assembly. Also, the valve reeds may bend during normal use and the valve reeds tend to be noisy during operation.
The prior art also discloses valve plate assemblies in which a flat resilient member is clamped over ports. Circular or somewhat parabolic shaped flaps are cut in the resilient member to form valves attached to the member by resilient hinges. The valves are positioned to cover the ports. This arrangement eliminates some of the problems with reed valves. However, closing of the valve flaps is limited by the limited force exerted by the resilient hinge. Also, additional components, such as a second rigid plate, are required to form both intake and exhaust valves.